1741. Communication Fiend（ｄｐ）

刷个简单的ＤＰ缓缓心情

１Ａ

 1 #include <iostream>

 2 #include<cstdio>

 3 #include<cstring>

 4 #include<algorithm>

 5 #include<stdlib.h>

 6 #include<vector>

 7 using namespace std;

 8 #define N 10010

 9 vector<int>q[N];

10 #define LL __int64

11 #define INF 1e10

12 LL dp[N][4];

13 int o[N];

14 struct node

15 {

16     int x,y,d;

17     char s[10];

18 }p[N];

19 int main()

20 {

21     int i,j,n,m;

22     scanf("%d%d",&n,&m);

23     for(i = 1; i <= m ; i++)

24     {

25         scanf("%d%d%d%s",&p[i].x,&p[i].y,&p[i].d,p[i].s);

26         q[p[i].y].push_back(i);

27     }

28     dp[i][1] = 0;

29     dp[i][2] = INF;

30     dp[i][3] = INF;

31     for(i = 2; i <= n ; i++)

32     {

33         dp[i][1] = dp[i][2] = dp[i][3] = INF;

34         for(j = 0 ; j < (int)q[i].size() ; j++)

35         {

36             int v = q[i][j],k,x = p[v].x,w = p[v].d;

37             if(strcmp(p[v].s,"Licensed")==0)

38             k = 1;

39             else if(strcmp(p[v].s,"Cracked")==0)

40             k = 2;

41             else k = 3;

42             if(k==1)

43             {

44                 dp[i][1] = min(dp[i][1],min(dp[x][1]+w,dp[x][2]+w));

45             }

46             else if(k==2)

47             {

48                 dp[i][2] = min(dp[i][2],min(dp[x][2]+w,dp[x][1]+w));

49                 dp[i][3] = min(dp[i][3],dp[x][3]+w);

50             }

51             else

52             {

53                 dp[i][3] = min(dp[i][3],dp[x][3]+w);

54                 dp[i][3] = min(dp[i][3],dp[x][2]+w);

55                 dp[i][3] = min(dp[i][3],dp[x][1]+w);

56             }

57         }

58     }

59     LL ans = INF;

60     for(i = 1; i <= 3 ; i++)

61     ans = min(ans,dp[n][i]);

62     if(ans==INF)

63     puts("Offline");

64     else

65     {

66         puts("Online");

67         printf("%I64d\n",ans);

68     }

69     return 0;

70 }

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